a. Field of the Invention
The subject invention relates to a new and improved air scrubber apparatus for removing particles and fumes from an air stream. More particularly, an apparatus is provided which first saturates the air stream to form a liquid-particulate agglomeration and then draws the air stream through a tortuous path defined by an arrangement of three baffles which function to separate the agglomeration from the air stream. The subject invention also includes a new and improved hopper which reduces turbulence of the air stream and is capable of accommodating a plurality of filtering devices for separating the particulates from the liquid.
b. Description of the Prior Art
As an example of the use of an air scrubber apparatus, during the drying of textiles the tumbling action caused by the rotating drums of the dryers results in small lint particles being shorn free of the materials, which are then carried away in the hot air exhaust. In large industrial applications, it has been found that a separate apparatus must be provided to remove the lint particles from the air stream prior to venting the air stream to the atmosphere. Original attempts to "scrub" the air involved simply passing the lint-laden air stream through filters to collect the lint particles. This method was not entirely satisfactory in that the collected lint occupied large amounts of space and, in addition, created a fire hazard. Further, as the filter became increasingly clogged with lint particles the drawing efficiency or "negative pressure" created by the scrubbing or collector apparatus would decrease. Maintaining a constant negative pressure relative to the dryers is necessary because if the drawing pressure of the lint collector apparatus is too small, the air stream will not be properly pulled through the lint collector and the lint will not be removed. On the other hand, if the negative pressure is too large, the hot air is drawn out of the dryers before it has a chance to dry the textiles, thus decreasing the efficiency of the dryers and increasing heating and operating costs. To alleviate these drawbacks, one form of prior art air scrubber or lint collector separates the air stream as it enters the collector apparatus, such that the lint particles are trapped in the liquid and thus form an agglomeration. The collector apparatus then separates the liquid-lint agglomeration from the air stream, so that the agglomeration can be filtered. This system was advantageous in that the moistened lint occupies a much smaller volume, and since it was moist, it created no fire hazard. In addition, since the air flow is not required to pass through filters, a constant negative pressure relative to the dryers could be substantially maintained.
Prior art liquid air scrubbers separate the liquid-lint agglomeration from the air stream by causing the air stream to impinge on a central baffle within the housing of the collector apparatus. The impingement of the air flow on the baffle results in a portion of the liquid-lint agglomeration being trapped by the baffle where it subsequently runs down into a collecting pan or hopper. It was found, however, that the baffle arrangement in the prior art apparatus could not effectively remove enough of the liquid-lint agglomeration as was necessary to provide adequate scrubbing of the air stream.
Another shortcoming of the prior art apparatus is that the water which cascades down the baffle towards the hopper could be reabsorbed by the air flow before it was filtered. More particularly, the hopper found in prior art devices, which defines the bottom of the housing, is generally of a truncated inverted pyramidal configuration, thus allowing the liquid-lint agglomeration to flow downwardly towards a central opening, where a filtering means is located. Thus, the inverted truncated pyramidal configuration provides only one collection point for the liquid-lint agglomeration. Hence, the prior art device could accommodate only one filtering means which must be frequently attended to. In addition, as the air stream passes over the inverted truncated pyramidal configuration, a great deal of turbulence results, which had the effect of stirring up the liquid-lint agglomeration collected in the hopper, thus causing some of the lint particles to be reabsorbed into the air stream and thus decreasing the efficiency of the apparatus.
Another shortcoming of the prior art apparatus relates to the physical distance between the lint removing device and the dryers. This distance directly affects the amount of drawing force or negative pressure which must be created by the apparatus for efficient operation. Since the distance from the dryers to the prior art device varies with different customers, the required negative pressure was found to be difficult to achieve since only minor variations in the negative pressure could be obtained by means of altering the fan speed of the prior art device.
Accordingly, considering the shortcomings of the prior art devices, it is among the objects of the subject invention to provide an apparatus for removing particulates from an air stream which has a baffle arrangement which effectively removes a liquid-particulate agglomeration from an air stream.
It is a further object of the subject invention to provide an apparatus for removing particulates from an air stream which has a new and improved hopper design that will reduce the turbulence of the air flow.
It is another object of the subject invention to provide an apparatus for removing particulates from an air stream which has a hopper design which can accommodate more than one filtering means for the liquid-particulate agglomeration.
It is still a further object of the subject invention to provide an apparatus for removing particulate from an air stream which includes a means for adjusting the negative pressure created by the apparatus.
Another object of the subject invention is to provide an apparatus for removing particulates from an air stream which isolates the trapped liquid-particulate agglomeration from the air stream as it runs down towards the hopper to prevent reabsorption of the particles.
It is still a further object of the subject invention to provide an apparatus for removing particulates from an air stream which inhibits the reabsorption of particles by the air stream as it flows past by the liquid-particulate agglomeration collected in the hopper.